<template>
  <div class="upload-file">
    <el-upload
      multiple
      :action="uploadFileUrl"
      :http-request="my_upload"
      :before-upload="handleBeforeUpload"
      :file-list="fileList"
      :limit="limit"
      :on-error="handleUploadError"
      :on-exceed="handleExceed"
      :on-success="handleUploadSuccess"
      :show-file-list="false"
      :headers="headers"
      class="upload-file-uploader"
      ref="fileUpload"
    >
      <!-- 上传按钮 -->
      <el-button size="mini" type="primary">选取文件</el-button>
      <!-- 上传提示 -->
      <div class="el-upload__tip" slot="tip" v-if="showTip">
        请上传
        <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
        <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join('/') }}</b></template>
        的文件
      </div>
    </el-upload>

    <!-- 文件列表 -->
    <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
      <li :key="file.url" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in fileList">
        <el-link :href="hrefFilters(file.url)" :underline="false" target="_blank">
          <span class="el-icon-document"> {{ getFileName(file) }} </span>
        </el-link>
        <div class="ele-upload-list__item-content-action">
          <el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
        </div>
      </li>
    </transition-group>
    <!--进度条-->
    <div v-if="showProgress" class="popContainer">
      <el-progress text-color="#ffffff" define-back-color="#0087e3" :text-inside="true"
                   :stroke-width="36" :format="format" :percentage="percentage"
                   style="top: 50%; left: 35%; width: 30%" status="success"></el-progress>
    </div>
  </div>
</template>

<script>
import { getToken } from '@/utils/auth'
import axios from 'axios'

export default {
  //官网原始文件上传
  name: 'SimpleFileUpload',
  props: {
    // 值
    value: [String, Object, Array],
    // 数量限制
    limit: {
      type: Number,
      default: 5
    },
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 5
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array,
      default: () => ['doc', 'xls', 'ppt', 'txt', 'pdf']
    },
    // 是否显示提示
    isShowTip: {
      type: Boolean,
      default: true
    }
  },
  data() {
    return {
      number: 0,
      showProgress: false,
      percentage: 0,
      uploadList: [],
      baseUrl: process.env.VUE_APP_BASE_API,
      uploadFileUrl: process.env.VUE_APP_BASE_API + '/common/upload', // 上传文件服务器地址
      headers: {
        Authorization: 'Bearer ' + getToken()
      },
      fileList: []
    }
  },
  watch: {
    value: {
      handler(val) {
        if (val) {
          let temp = 1
          // 首先将值转为数组
          const list = Array.isArray(val) ? val : this.value.split(',')
          // 然后将数组转为对象数组
          this.fileList = list.map(item => {
            if (typeof item === 'string') {
              item = { name: item, url: item }
            }
            item.uid = item.uid || new Date().getTime() + temp++
            return item
          })
        } else {
          this.fileList = []
          return []
        }
      },
      deep: true,
      immediate: true
    }
  },
  computed: {
    // 是否显示提示
    showTip() {
      return this.isShowTip && (this.fileType || this.fileSize)
    }
  },
  methods: {
    format(percentage) {
      return percentage === 100 ? '100%' : `上传中 ${percentage}%`
    },
    my_upload(uploader) {
      let form = new FormData()
      form.append('file', uploader.file)
      axios({
        method: 'post',
        headers: this.headers,
        url: this.uploadFileUrl,//自定义上传url
        data: form,
        onUploadProgress: progressEvent => {
          let percent = (progressEvent.loaded / progressEvent.total * 100) | 0
          percent = percent < 5 ? 2 : percent - 2
          console.log('上传进度:' + percent)
          this.percentage = Math.floor(percent)
          uploader.onProgress({ percent: percent })//调用uploader的进度回调
        }
      }).then((res,file) => {
        console.log('上传返回结果:')
        console.log(res)
        if (res.data.code === 200) {
          console.log('上传完成')
          this.percentage = 100
          this.handleUploadSuccess(res.data,file)
        } else {
          this.$message.error('上传失败')
        }
      }).catch((err) => {
        console.log('上传出错')
        console.log(err)
        this.$message.error(err)
      })
    },

    hrefFilters(url) {
      return this.baseUrl + url.split('____')[0]
    },
    // 上传前校检格式和大小
    handleBeforeUpload(file) {
      console.log('上传文件大小:' + file.size)
      // 校检文件类型
      if (this.fileType) {
        const fileName = file.name.split('.')
        const fileExt = fileName[fileName.length - 1]
        const isTypeOk = this.fileType.indexOf(fileExt) >= 0
        if (!isTypeOk) {
          this.$modal.msgError(`文件格式不正确, 请上传${this.fileType.join('/')}格式文件!`)
          return false
        }
      }
      // 校检文件大小
      if (this.fileSize) {
        const isLt = file.size / 1024 / 1024 < this.fileSize
        if (!isLt) {
          this.$modal.msgError(`上传文件大小不能超过 ${this.fileSize} MB!`)
          return false
        }
      }
      this.showProgress = true
      this.number++
      return true
    },
    // 文件个数超出
    handleExceed() {
      this.$modal.msgError(`上传文件数量不能超过 ${this.limit} 个!`)
    },
    // 上传失败
    handleUploadError(err) {
      console.log(err)
      this.$modal.msgError('上传文件失败，请重试')
    },
    // 上传成功回调
    handleUploadSuccess(res, file) {
      console.log('上传成功回调')
      console.log(res)
      if (res.code === 200) {
        console.log('上传成功!')
        console.log(res)
        this.uploadList.push({
          name: res.originalFilename,
          url: res.url + '____' + res.originalFilename
        })
        this.uploadedSuccessfully()
      } else {
        console.log('上传失败!')
        this.number--
        this.$modal.msgError(res.msg)
        this.$refs.fileUpload.handleRemove(file)
        this.uploadedSuccessfully()
      }
    },
    // 删除文件
    handleDelete(index) {
      this.fileList.splice(index, 1)
      this.$emit('input', this.listToString(this.fileList))
    },
    // 上传结束处理
    uploadedSuccessfully() {
      if (this.number > 0 && this.uploadList.length === this.number) {
        this.fileList = this.fileList.concat(this.uploadList)
        this.uploadList = []
        this.number = 0
        this.$emit('input', this.listToString(this.fileList))
        this.showProgress = false
        this.percentage = 0
      }
    },
    // 获取文件名称,文件名格式由三部分构成：上传后重命名的文件名____原文件名
    getFileName(name) {
      let n = name.name.split('____')
      return n.length > 1 ? n[1] : n[0]
    },
    // 对象转成指定字符串分隔
    listToString(list, separator) {
      let str = ''
      separator = separator || ','
      for (let i in list) {
        str += list[i].url + separator
      }
      return str !== '' ? str.substring(0, str.length - 1) : ''
    }
  }
}
</script>

<style scoped lang="scss">

.popContainer {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 999999;
  background: rgba(0, 0, 0, 0.6);
}

.upload-file-uploader {
  margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}

.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}

.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>
